Oxygen fractionation in dense molecular clouds
GERIN, Maryvonne
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
ROUEFF, Evelyne
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
PETIT, Franck Le
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
PETY, Jerome
Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
< Reduce
Institut de RadioAstronomie Millimétrique [IRAM]
Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)]
Language
en
Article de revue
This item was published in
Monthly Notices of the Royal Astronomical Society. 2019-03-06, vol. 485, n° 4, p. 5777-5789
Oxford University Press (OUP): Policy P - Oxford Open Option A
English Abstract
We have developed the first gas-grain chemical model for oxygen fractionation (also including sulphur fractionation) in dense molecular clouds, demonstrating that gas-phase chemistry generates variable oxygen fractionation ...Read more >
We have developed the first gas-grain chemical model for oxygen fractionation (also including sulphur fractionation) in dense molecular clouds, demonstrating that gas-phase chemistry generates variable oxygen fractionation levels, with a particularly strong effect for NO, SO, O2, and SO2. This large effect is due to the efficiency of the neutral 18 O + NO, 18 O + SO, and 18 O + O2 exchange reactions. The modeling results were compared to new and existing observed isotopic ratios in a selection of cold cores. The good agreement between model and observations requires that the gas-phase abundance of neutral oxygen atoms is large in the observed regions. The S 16 O/S 18 O ratio is predicted to vary substantially over time showing that it can be used as a sensitive chemical proxy for matter evolution in dense molecular clouds.Read less <
English Keywords
ISM: abundances
ISM: clouds
Physical Data and Processes: astrochemistry
Origin
Hal imported